Originally Posted by gchristophi

If the dump valve was leaking before it was stripped the boost may have been turned up to compensate. If the valve has since been fixed then you will have too much boost.

If you are making 1.5 bar on a -34 then either the wastegate is faulty and isn't opening properly or there is too much preload on the actuator. You should only have around 3mm of preload on the actuator. Adjust the actuator until it just slips onto the wastegate arm pin and then add two full turns and then refit to the wastegate arm pin. It should take a little bit of effort to stretch it on but not too much.

If still overboosts then the wastegate is likely to be at fault.